Depression is a terrible thing. People struggle to describe it to those who aren't subject to it: darkness, pointlessness, worthlessness; a black dog, perhaps, or a nuclear winter of the soul. There are often suicidal thoughts, which can dominate consciousness. Depressed people can't concentrate, can't think, feel lethargic, guilty, worthless and irritable. There may well be disturbance in sleep, and in eating and digestion. Some turn to drugs or drink. Those in its grip often seem addicted to suffering, helpless and hopeless. There is inadequate understanding of what it is about, why it has taken such a hold.

And, of course, there's no reason why cricketers more than anyone else should be immune: the image of Marcus Trescothick hunched up in a corner of an electronic-goods shop at Heathrow while his Somerset team-mates prepared to board a flight to Abu Dhabi for a pre-season tournament remains a haunting one even four years later.

For sportsmen and women - but in particular men - depression has often been a badge of shame, especially in a world that values confidence, courage and the supposedly manly virtues of strength and assertiveness. When Trescothick's return home from England's tour of India in early 2006 was first explained, it was put down to a virus, which later changed to a "stress-related illness", still the terminology often used when his condition is discussed today. By the time Mike Yardy left the World Cup in 2011, the ECB did feel able to cite depression as the reason. This was a step in the right direction, but the reluctance to be open in the first place about Trescothick's plight stems, I believe, from a long-held idea that we should be thick-skinned and resilient; that to admit fear or unhappiness would be to lay oneself open not only to ridicule but to being dropped from the side (the very word "dropped" hints at the link to early-life anxieties and the insecurities of the baby). We are not supposed to be vulnerable, certainly not to show vulnerability. We don't wear our hearts on our sleeves - particularly not we English.

The proliferation of coaches and backroom staff over recent years may, paradoxically, risk making the situation harder. In the old days, it would be one's closest team-mates to whom one might admit anxiety; they are, after all, in the same boat, and may have a less judgmental or executive response. But the willingness of players such as Trescothick, Yardy, the outwardly chipper Matthew Hoggard, the former Derbyshire captain Luke Sutton, and even that tremendous competitor Andrew Flintoff to admit to their feelings may suggest change at a societal level: depression is not quite the taboo it once was. And, unlike Trescothick and Yardy - who both felt compelled to explain their departures from tours - the others were under no obligation to talk about their emotions.

There are two separable things here: the reluctance to admit to feeling low; and the increasing willingness of players to overcome that reluctance. On the one hand, in order to be a good sportsman one must be tough, a quality which can be weakened by self-doubt and fear. Players may therefore rightly be apprehensive about too much self-doubt. On top of this, there may be a reinforcement of such apprehension from the macho attitude of those who mock ordinary doubt. It is this that leads to the shame. However, self-doubt can be a necessary resource leading to work, improvement and, in the end, greater strength, both technically and emotionally.

Keeping things bottled up can be disastrous. The New Zealand seamer Iain O'Brien, another sufferer who has felt able to go public about his condition, alluded to this process when he admitted that the potential consequences of saying nothing were far worse than the supposed shame of opening up. "I don't want to be one of those statistics," he said, referring to those cricketers - and there have been too many - who have ended up killing themselves.

Several have now risked this feared ridicule and come out as depressed. O'Brien himself was encouraged to do so after listening to a radio programme on the subject, hosted by Michael Vaughan in 2011, in which Hoggard said he felt like crying as he reached the end of his run-up during his final Test appearance, in Hamilton. The revelation was a poignant one: Vaughan was Hoggard's captain in that game. Not long before my time as a player, bowlers were reluctant to show emotion even when they took a wicket; Hoggard's openness was an encouraging sign of the times. Equally refreshing has been the respect accorded by the press to both Trescothick and Yardy. Despite inevitable pressure from their editors to get the story, journalists have been sensitive enough to allow the players to tell it in their own time. And admitting the extent of the problem may be the first step towards healing and repair.

So why the apparently growing need for healing and repair? Has depression become more prevalent for cricketers? It may be that the speeding up of life, the demand for quick fixes, the "taking the waiting out of wanting" - as the 1980s credit-card advertisement so pithily put it - make for more depression, not less. Such a culture seems to require happiness, briskness, a capacity to succeed early, and in overtly measurable ways. So cricket, with its waiting around, its lonely trudge back to the pavilion, its longueurs, its rain-breaks, may offer a testing task to the modern young man or woman.

But there must be more to it than that. For depression often arises in relation to loss, especially loss that the person cannot, for whatever reason, successfully mourn. It may be of a significant other; it may be more a matter of long separations and loneliness; or it may be of prestige, position or power, such as comes with loss of form, or decline with age, or from a realisation that one is not the only pebble on the beach. Cricket is no exception. Careers are short - few go on beyond their late thirties, unless offered a juicy contract by a Twenty20 franchise. Since most professional cricketers are in it primarily because they love the game, and since it has such intensities of effort, elation and disappointment, the loss related to retirement is bound to be painful. By the time you retire, your contemporaries in other fields will have moved onwards and upwards, while you have to start afresh. Most ex-professional cricketers will never again be so directly involved in doing what they are passionate about. Even jobs which involve the skills and knowledge of the sport - umpiring, coaching, commentating or writing - may seem less intensely vocational than playing at a high level, and few go into second careers which involve them as cricket did. Shakespeare, naturally, had a phrase for this general truth about life: "And every fair from fair sometime declines, by chance or nature's changing course untrimmed." For the cricketer, nature's change of course can be too early, too fast, and too damaging. Hoggard, remember, was discarded by England's Test team virtually overnight during that tour of New Zealand.

Depression is an arrangement by which we keep from ourselves the degree of hostility we feel, turning it on ourselves, but in a way inflicting it on others indirectly

Loss is harder to bear and more likely to turn into depression if one is full of hatred. All losses evoke some anger: how dare you leave me! But for some it is particularly strong; loss and separation may evoke bitterness and anger such that in the imagination there are murderous impulses to the person one misses. New Zealand's Lou Vincent, who was dropped on more than one occasion, told the Independent: "I was passionate about playing for New Zealand. But how many times can you be let down by something that you love? It's like the love of your life, she takes you back and she drops you. How many times can you have your heart broken?" Since that person - or, in the case of Vincent, that organisation - is often the very person one would turn to in a crisis, the hostility towards them, and the ensuing guilt, leaves the subject doubly alone. It is harder in such cases to mourn and move on.

Closely related to letting go of one's passionate activity is decline in form. Failure is stark and public. Like a king deposed, the dismissed batsman has to leave the arena; the bowler is merely taken off. The batsman may have to wait days for another chance. One little error, one good delivery, can result in total exclusion. And such outcomes are reported instantly to the public. The starkness of a scorecard that reads "Gatting b Warne 4" tells the casual observer nothing about the drama of the moment. Luck plays a big part. What's more, failures which may be a result of bad luck eat away at one's confidence, making form not only mercurial and uncontrollable, but self-fulfilling, the outcome of self-denigration. There can so easily be a vicious circle.

One type of such destructiveness happens when the person is prone to grievance: the glass is always half empty. Such a person is addicted to suffering and to inflicting suffering; he focuses on what he doesn't have, rather than what he does. He even prefers suffering - perhaps in dramatic or histrionic ways - to making the best of a bad job, and appreciating what he has. Depressed people feel passive, have no energy, a damaged sense of self. They may trade on this, stoking up the role of victim and, without realising, choose it over the ordinary struggle involved in getting on with things. As Iain O'Brien perceptively put it: "Wrapped up in it is how you value and see yourself."

Depression is more likely, too, for someone who at heart feels fraudulent, which itself is related to the weight of expectation felt by international sportsmen. Then - because that fraudulence may have been repressed - the depression can be experienced as something alien to the conscious self, a black dog, something that comes from outer space, or from a blue sky. Reflecting on his swift demise, Hoggard told Vaughan: "I was just thinking that the world was against me, that I'm rubbish, that I can't do this anymore. It just got on top of me. The self-doubt was huge."

People may be depressed at failure, but also at success. How often do we see a tennis player lose his serve immediately after breaking his opponent's? I think this is to do with guilt at triumph, at superiority. We may, in hidden ways, gloat over our defeated opponent or upstaged rival, and this may be so hard to bear that we contrive to fail rather than risk it. We may also discover that success isn't the panacea we have expected. No doubt post-natal depression has many causes, but one might be: this is not a bed of roses!

This may be hard to see in sport, partly because, as spectators, journalists and readers, our attention is so fixed on success; and those who are consistently successful are better able to accept their aggression and manage it well. But I am convinced, partly from my own experience, that we often do draw back from success, reluctant to risk gloating over a defeated rival who in the depths of our minds evokes a father or a sibling. We may also identify with that part of the other which wishes to knock the successful off their pedestals.

Depression, then, is an arrangement by which we keep from ourselves the degree of hostility we feel, turning it on ourselves, but in a way inflicting it on others indirectly. The depressed person is savaged by a judgmental inner voice, whose punitiveness mirrors the often unconscious wish to hurt the person felt to have let him down. He may also displace his bitterness and anger from the lost person on to an available target (an umpire, for example), like someone who comes home from a humiliating day at work and kicks the cat.

So the cricketer has to tolerate loss of form - and with it, perhaps, his place in the team, even his career - and the early ending of at least one of the loves of his life. It can, as Lou Vincent implied, feel like the end of a love affair, or like a sticky patch in a marriage; loss of, or decline in, bodily skill can, like later mental decline, be experienced as the surrender of the essential self. No wonder some find it unbearable. As David Frith catalogued in Silence of the Heart, published in 2001, no fewer than 150 professional cricketers had by then committed suicide. And this must have been the tip of a much larger iceberg of players who had been depressed but not gone to this ultimate. During his career, the successful cricketer also spends a lot of time travelling. Some find this separation from loved ones, especially at great distances, troublesome. One reason why, on the whole, teams do so much better at home lies here. The depression suffered by both Trescothick and Yardy was exacerbated by being far away from the people who knew them best and by the lack of a comparable support network on tour.

Of course, it can be hard to know what is going on in people's minds. But I was occasionally aware of a player being in difficulties, perhaps depressed, especially on tour. And loneliness was often at the heart of it. Some found big hotels in large cities anonymous and not conducive to feeling safe and at home. By contrast, the communal experience of staying in circuit houses or small hotels in India or Pakistan back in the 1970s, usually outside the main cities, could create a feeling of togetherness, humour and sociability that was much harder to find in the five-star luxury of a modern big-city hotel; some would stay in their rooms evening after evening, eating dinner on their own. Such patterns could be hard to notice when there was no place of focus once we were away from the dressing room, the manager's room, or the team bus, and the habit could become more addictive if morale dropped lower. A vicious circle of alienation and loneliness could ensue if no one became aware of it.

Such scenarios also happen in England. There are county cricketers who find it hard to be away even from their home town. One county captain I knew made himself available for dinner with a team member who was prone to depression during every away match. For some, loneliness is an outcome of the sheer routine of socialising on a cricket tour. A certain sameness can become limiting. Such people need other, perhaps more culturally varied, stimuli. Sometimes, one needs to get away from the close cricketing family.

During my playing days, tactful help and awareness of the problem prevented it from getting a grip on a few individuals. Captains and managers vary greatly in this important ability to be sensitive to people when they become unhappy, or aggrieved, or bored. One of Doug Insole's many assets as England manager was in this area. It would be hard to write "sensitivity to potential depression" into the job description of today's England coach. But ordinary human consideration, concern for everyone in the party, and tact should be. And occasionally that would extend to recognising that something more than ordinary friendly management is required, that a player needs to get specialist treatment, and may even have to leave the team for the time being.

Despite all this, the sporting arena itself can provide an antidote, since sport does permit aggression. Many people give the impression that only on the field can they be thoroughly and spontaneously themselves, though here again, this can make retirement, or absence through injury or poor form, feel like a loss of the true self. But at least the sportsman might be helped to avoid depression by the fact that sport has aggression built in. What is not so readily permitted in its ethos is envious rivalry with one's own team-mates. I think it's impossible not to feel some envy at the successes of a colleague who is vying with you for a place, and this can arouse guilt and shame. So aggression can be a problem when one can't enlist it, and also when one can but with too much or inappropriate venom or force.

Sporting teams are, as I've suggested, tough social groups, and the effect can be amplified in cricket, where the participants spend so much time with each other. Vulnerability may not be respected. Professional cricketers can be quick and perceptive, often cruelly so. The dressing room is not an easy place in which to hide. The rough and tumble, the sarcasm and mockery, are mostly friendly, but can also become bullying, the stuff of small boys in school playgrounds. In short, for some cricketers, aggression causes problems rather than provides a safety valve.

Perhaps what I have suggested in relation to both loss and aggression could be summed up thus: what doesn't kill you - or make you depressed - leaves you stronger. The tipping point can be hard to predict, perhaps the outcome of chance and the presence or absence of the right person, or the right piece of good luck, at the right time. Sport can indeed be an antidote to depression. I remember a time when I was in turmoil in my personal life; batting and playing, however difficult to do well, provided an arena in which life's aims and objectives were for a while simplified. It is not easy to hit a hard ball delivered with speed and skill by a fellow professional, but facing it does, like imminent execution, concentrate the mind.

And yet there is no escaping the profundity of depression - nor, as I noted at the beginning, the difficulty among non-sufferers of grasping it. As Trescothick said: "There's so much to it. People say: 'Pull yourself together, move on.' I wish it was that simple. You try to forget, but it takes over your whole life." Our understanding of this crippling condition, especially in the sporting arena, may merely have scratched the surface. And even when something is recognised and acknowledged, it is still hard to know what's best for the sufferer. Sportsmen want, above all, quick fixes, as with physical injury. The trouble is, established patterns can take a long time to shift.

Mike Brearley played in 39 Tests for England between 1977 and 1981, captaining them in 31, of which 18 were won and only four lost. He is a practising psychoanalyst